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Finding the Fourth Proportional to 85.70, 118.17 and 74.09

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Solution

The fourth proportional to 85.70, 118.17 and 74.09 is: 102.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.70 : 118.17 = 74.09 : x
  2. Step 2: Convert to fraction form
    85.70/118.17 = 74.09/x
  3. Step 3: Cross multiply
    85.70x = 118.17 × 74.09
  4. Step 4: Simplify right side
    85.70x = 8,755.22
  5. Step 5: Solve for x
    x = 8,755.22/85.70
  6. Step 6: Final answer
    x = 102.16

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.